Alter table to add constraint with name : Add Constraint « Constraints « Oracle PL / SQL






  1. Oracle PL / SQL
  2. Constraints
  3. Add Constraint

Alter table to add constraint with name

 

SQL> --Unique Key
SQL>
SQL>
SQL> create table myTable (
  2    a number unique,
  3    b number
  4  );

Table created.

SQL>
SQL>
SQL> alter table myTable add constraint uq_ri_b unique (b);

Table altered.

SQL>
SQL>
SQL> insert into myTable values (4,   5);

1 row created.

SQL> insert into myTable values (2,   1);

1 row created.

SQL> insert into myTable values (2,   1); -- Dup
  2  insert into myTable values (9,   8);
insert into myTable values (2,   1); -- Dup
                                   *
ERROR at line 1:
ORA-00911: invalid character


SQL> insert into myTable values (6,   9);

1 row created.

SQL> insert into myTable values (null,9);
insert into myTable values (null,9)
*
ERROR at line 1:
ORA-00001: unique constraint (SYS.UQ_RI_B) violated


SQL> insert into myTable values (null,9);
insert into myTable values (null,9)
*
ERROR at line 1:
ORA-00001: unique constraint (SYS.UQ_RI_B) violated


SQL>
SQL> select * from myTable;

         A          B
---------- ----------
         4          5
         2          1
         6          9

SQL>
SQL> drop table myTable;

Table dropped.

SQL>
SQL>








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